Evil thoughts, negative emotions like anger, a sense of feeling “dirty” and “unclean”, are being purged from the body through the feet in the form of yellow pus in the dream.

This is a “detoxing” dream, a spiritual or subconscious “detoxing” if you will.

In traditional Chinese dream interpretation, and in some Taoist folklore, this dream is a manifestation of the “evil spirits” being purged from the person as a result of a Taoist cleansing ceremony. Sometimes actual yellow pus will ooze from the foot, according to Taoist folklore, and the Taoist priests point to the actual yellow pus as physical proof that the “evilness” is being “purged” from the body, and the Taoist priest will take credit for his incantations and ceremonies and justify his exorbitant fee.